The present invention relates generally to data networking and, more specifically, to providing MVPN (Multicast Virtual Private Network) services using IPv4-in-IPv6 address translation over an IPv6 network.
To accommodate the explosive growth of the Internet, a very large number of network nodes have been configured to employ IP (Internet Protocol). Internet Protocol version 4 (IPv4) is the most widely deployed version of IP. However, the broad acceptance of IP has placed considerable strain on the 32-bit addressing scheme available in IPv4. Consequently, the Internet Engineering Task Force (IETF) developed a new Internet Protocol Standard, Internet Protocol version 6 (IPv6). Advantages of IPv6 include an enormous expansion in the available address space to accommodate both greater ubiquity of Internet-enabled devices as well as less reliance on cumbersome network address translation schemes which have been utilized to conserve addresses. IPv6 also provides highly useful auto-configuration capabilities.
IP networks include service provider networks which often use their IP backbone to provide IP VPNs for its customers. Virtual Private Networks serve as network overlays on IP network infrastructures. Many companies have created their own VPN to accommodate the needs of remote employees and distant offices. In order for traffic within a VPN to travel from one VPN site to another, special protocols and procedures must be implemented by the VPN service provider. One method is described in IETF draft “Multicast in MPLS/BGP IP VPNs” Rosen et al., (draft-rosen-vpn-mcast-08.txt), December 2004. See also, “BGP/MPLS VPNs”, RFC 2547, Category: Informational, E. Rosen, Y. Rekhter, March 1999. Traffic sent between VPNs is received at a provider edge (PE) router. A PE which attaches to a particular multicast-enabled VPN belongs to a corresponding Multicast Domain. For each Multicast Domain, there is a default Multicast Distribution Tree (MDT), through the backbone, connecting all of the PEs that belong to that Multicast Domain. The MDTs are created by running Protocol Independent Multicast (PIM) in the backbone, and in general an MDT also includes P (provider) routers on the paths between the PE routers. In this method, all PEs in a MDT group receive VPN traffic and configuration changes are required at the service provider PEs.
It is desired to provide scalable IPv4 and IPv6 unicast and multicast VPNs over one or more service provider networks so that IPv4 VPNs run better when IPv6 is deployed in the service provider network. It is further desired that the system and method which provides the scalable VPNs over the service provider networks run in CE (customer edge) routers rather than PE routers such that the termination endpoints for the VPN are in the CE routers.